I'm developing a simple app, with several static screens, just. I get working passing from first fragment, but can't go back to any screen ever.
I saw some videos, like shorturl.at/jFPRY, but in any cases makes work. In my MainActivity I have the OnCreate method, where I save the instance, set the layout, and add a Listener to options on my menu itens.
In the first click, when I open the app, it goes to correct destiny. However, when I click another item it does nothing, stucked. I need to set the Fragments bidirectional, in other words, the user can view any fragment in any moment from any fragment.
My OnCreate method:
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
binding = ActivityMainBinding.inflate(layoutInflater)
setContentView(binding.root)
setSupportActionBar(binding.appBarMain.toolbar)
val drawerLayout: DrawerLayout = binding.drawerLayout
val navView: NavigationView = binding.navView
navView.setNavigationItemSelectedListener {
when (it.itemId) {
R.id.nav_conheca_a_UFTM -> {
supportFragmentManager.beginTransaction()
.replace(R.id.drawer_layout, ConhecaUftmFragment())
.commit()
// Remove the other operations
supportFragmentManager.beginTransaction().addToBackStack(null);
}
R.id.nav_calendario_academico -> {
supportFragmentManager.beginTransaction()
.replace(R.id.drawer_layout, GalleryFragment())
.commit()
// Remove the other operations
supportFragmentManager.beginTransaction().addToBackStack(null);
}
R.id.nav_mural_de_informacoes -> {
supportFragmentManager.beginTransaction()
.replace(R.id.drawer_layout, CalendarioFragment())
.commit()
// Remove the other operations
supportFragmentManager.beginTransaction().addToBackStack(null);
}
}
it.isChecked = true
drawerLayout.closeDrawers()
true
}
supportActionBar?.apply {
setDisplayHomeAsUpEnabled(true)
}
navController = Navigation.findNavController(this, R.id.nav_host_fragment_content_main)
val appBarConfiguration = AppBarConfiguration(navController.graph, drawerLayout)
NavigationUI.setupWithNavController(binding.appBarMain.toolbar, navController, appBarConfiguration)
NavigationUI.setupActionBarWithNavController(this, navController, drawerLayout)
}
I have also the method onSupportNavigateUp:
override fun onSupportNavigateUp(): Boolean {
val navController = this.findNavController(id.nav_host_fragment_content_main)
return navController.navigateUp()
}
And here is an example of Fragment that I have:
class GalleryFragment : Fragment() {
override fun onCreateView(
inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?
): View? {
val view = inflater.inflate(R.layout.fragment_calendario_academico, container, false)
/* view.setOnClickListener(){ Navigation.findNavController(view).
navigate(R.id.conhecauftmToaprimorando)
}*/
return view
}
override fun onDestroyView() {
super.onDestroyView()
}
}
I will pass my GitHub link, if anyone can help to fix this issue.
First approach would be to not use FragmentTransactions when you using NavComponent.
If you have the MenuOptions on the MainActivity layout (which I don't recommend, it should go on every fragment, so the MenuOptions are correlated to the current fragment) you can define your navigations in the nav_graph.xml and use them in the MainActivity through NavigationDirections object.
Please visit https://developer.android.com/guide/navigation/navigation-getting-started for more info.
If you want to come back from GalleryFragment to where you have defined the destination of the Popback behaviour, you should call: findNavController.popBackStack()
Related
Example of what i'm trying to achieve https://i.stack.imgur.com/lhp10.png
I'm stuck on the part where i need to switch to createUserFragment from defaultFragment
i attached this to my button, but nothing happens when i press it, not sure what's wrong there
MainActivity
class MainActivity : AppCompatActivity() {
lateinit var appBarConfiguration: AppBarConfiguration
lateinit var navController: NavController
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
navController = findNavController(R.id.hostFragment)
appBarConfiguration = AppBarConfiguration(navController.graph,drawer_layout)
NavigationUI.setupActionBarWithNavController(this, navController,drawer_layout)
NavigationUI.setupWithNavController(navigation_drawer,navController)
}
}
override fun onSupportNavigateUp(): Boolean {
return NavigationUI.navigateUp(navController,appBarConfiguration)
}
defaultFragment
class defaultFragment : Fragment() {
private lateinit var binding: defaultFragmentBinding
override fun onCreateView(
inflater: LayoutInflater, container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
// Inflate the layout for this fragment
binding = defaultFragmentBinding.inflate(inflater)
return (binding.root)
}
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
binding.createNewBlankFAB.setOnClickListener{
val transaction = (activity as MainActivity).supportFragmentManager.beginTransaction()
transaction.replace(R.id.defaultFragment, createUserFragment())
transaction.disallowAddToBackStack()
transaction.commit()
}
}
}
My questions are:
1)How can i fix my thing?
2)Will it work properly? I.e no memory leaks or some other funky stuff
3)Do i have to use another fragment for data input or maybe there's another way?
UPDATE
I stil have no idea how this works, but apparently i was replacing wrong fragment, i switched this R.id.defaultFragment in transaction.replace to R.id.hostFragment from which, i assume, all other fragments spawn, but now it just spawn on top of my existing fragment and the drawer button doesn't change its state, i guess i have to either do all of this differently or somehow pass to the drawer navigation information that current fragment was changed?
This is how we navigate within fragments in Navigation component library . We use navigate to then id of the destination Fragment which is defined in navgraph
binding.createNewBlankFAB.setOnClickListener{
Navigation.findNavController(view).navigate(R.id.createUserFragment);
}
I think you have to call "transaction.add" instead of "replace" since you are calling your fragment from an activity. Replace is called when you call a fragment from another fragment, I believe.
I want to show navigation drawer icon instead of Back button on a certain fragment. I created the App with Navigation graph.
Let's say i have 2 fragments (LoginFragment and DashboardFragment) and one activity (MainActivity)
MainActivity.kt
class MainActivity : AppCompatActivity() {
lateinit var drawerLayout: DrawerLayout
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
val binding = DataBindingUtil.setContentView<ActivityMainBinding>(this, R.layout.activity_main)
drawerLayout = binding.drawerLayout
val navController = this.findNavController(R.id.myNavHostFragment)
// prevent nav gesture if not on start destination
navController.addOnDestinationChangedListener { nc: NavController, nd: NavDestination, args: Bundle? ->
if (nd.id == nc.graph.startDestination) {
drawerLayout.setDrawerLockMode(DrawerLayout.LOCK_MODE_UNLOCKED)
} else {
drawerLayout.setDrawerLockMode(DrawerLayout.LOCK_MODE_LOCKED_CLOSED)
}
}
NavigationUI.setupActionBarWithNavController(this, navController, drawerLayout)
NavigationUI.setupWithNavController(binding.navView, navController)
}
// Set up the back button on action bar
override fun onSupportNavigateUp(): Boolean {
val navController = this.findNavController(R.id.myNavHostFragment)
return NavigationUI.navigateUp(navController, drawerLayout)
}
}
LoginFragment.kt
class LoginFragment : Fragment() {
override fun onCreateView(
inflater: LayoutInflater, container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
val binding:FragmentLoginBinding = DataBindingUtil.inflate(inflater,
R.layout.fragment_login, container, false)
// Hide the Action bar
(activity as AppCompatActivity).supportActionBar?.hide()
binding.loginButton.setOnClickListener {
//Some unimportant validation
}
return binding.root
}
}
DashboardFragment.kt
class DashboardFragment : Fragment() {
lateinit var binding : FragmentDashboardBinding
override fun onCreateView(
inflater: LayoutInflater, container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
// Binding object for this fragment and the layout
binding = DataBindingUtil.inflate(inflater,
R.layout.fragment_dashboard, container, false)
//Navigate to Product stock fragment when clicked
binding.productStockButton.setOnClickListener(Navigation.createNavigateOnClickListener(
R.id.action_dashboardFragment_to_productStockOutletList
))
//Navigate to Switching History fragment when clicked
binding.switchingHistoryButton.setOnClickListener(Navigation.createNavigateOnClickListener(
R.id.action_dashboardFragment_to_switchingHistoryFragment
))
//Navigate to Outlet List fragment for Outstanding Product when clicked
binding.outstandingOrderButton.setOnClickListener(Navigation.createNavigateOnClickListener(
R.id.action_dashboardFragment_to_outletListFragment
))
// Set action bar title to "Main Dashboard"
(activity as AppCompatActivity).supportActionBar?.title = "Main Dashboard"
// Declare that this fragment has menu
setHasOptionsMenu(true)
(activity as AppCompatActivity).supportActionBar?.show()
(activity as AppCompatActivity).supportActionBar?.setDisplayHomeAsUpEnabled(false)
//Return.... i don't know.
return binding.root
}
override fun onCreateOptionsMenu(menu: Menu, inflater: MenuInflater) {
super.onCreateOptionsMenu(menu, inflater)
inflater?.inflate(R.menu.nav_overflow_menu, menu)
}
}
And this is my Navigation graph (I set up LoginFragment as home)
I want to show the navigation drawer in the DashboardFragment instead of LoginFragment. (With LoginFragment still be the start of the graph). I already hide the Up button of the DashboardFragment
This is the current look of the dashboard. As you can see that the back button is already gone.
Is there anything i can do with it ? If there is something unclear let me know.
try this I hope that it will help you, this will hide actionBar on LoginFragment as it's the startDestination on graph and show it otherwise
class MainActivity : AppCompatActivity() {
private lateinit var appBarConfiguration: AppBarConfiguration
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
val toolbar: Toolbar = findViewById(R.id.toolbar)
setSupportActionBar(toolbar)
val drawerLayout: DrawerLayout = findViewById(R.id.drawer_layout)
val navView: NavigationView = findViewById(R.id.nav_view)
val navController = findNavController(R.id.nav_host_fragment)
// prevent nav gesture if not on start destination
navController.addOnDestinationChangedListener { nc: NavController, nd: NavDestination, args: Bundle? ->
if (nd.id == nc.graph.startDestination) {
drawerLayout.setDrawerLockMode(DrawerLayout.LOCK_MODE_LOCKED_CLOSED)
supportActionBar?.hide()
} else {
supportActionBar?.show()
drawerLayout.setDrawerLockMode(DrawerLayout.LOCK_MODE_UNLOCKED)
}
}
// here this ids are form fragment which should show navigation icon
appBarConfiguration = AppBarConfiguration(setOf(
R.id.nav_home,R.id.nav_gallery, R.id.nav_slideshow), drawerLayout)
setupActionBarWithNavController(navController, appBarConfiguration)
navView.setupWithNavController(navController)
}
override fun onCreateOptionsMenu(menu: Menu): Boolean {
// Inflate the menu; this adds items to the action bar if it is present.
menuInflater.inflate(R.menu.main, menu)
return true
}
override fun onSupportNavigateUp(): Boolean {
val navController = findNavController(R.id.nav_host_fragment)
return navController.navigateUp(appBarConfiguration) || super.onSupportNavigateUp()
}
}
I know this already asked a few times, but I still don't get anything after all (I'm quite new in android development).
So i set up my back button in the MainActivity.kt like this:
class MainActivity : AppCompatActivity() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
val binding = DataBindingUtil.setContentView<ActivityMainBinding>(this, R.layout.activity_main)
val navController = this.findNavController(R.id.myNavHostFragment)
NavigationUI.setupActionBarWithNavController(this, navController)
supportActionBar?.setDisplayHomeAsUpEnabled(false)
}
// Set up the back button on action bar
override fun onSupportNavigateUp(): Boolean {
val navController = this.findNavController(R.id.myNavHostFragment)
return navController.navigateUp()
}
}
What I want is that this back button is disabled in some fragments, so I tried to override the onBackPressed() function (It is what most people on the internet told) in one of the fragments:
class DashboardFragment : Fragment() {
override fun onCreateView(
inflater: LayoutInflater, container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
// Declare that this fragment has menu
setHasOptionsMenu(true)
// Set action bar title to "Main Dashboard"
(activity as AppCompatActivity).supportActionBar?.title = "Main Dashboard"
// Binding object for this fragment and the layout
val binding: FragmentDashboardBinding = DataBindingUtil.inflate(inflater, R.layout.fragment_dashboard, container, false)
//Some codes here//
return binding.root
}
// This is where the error occured
override fun onBackPressed() {
super.onBackPressed()
}
override fun onCreateOptionsMenu(menu: Menu, inflater: MenuInflater) {
super.onCreateOptionsMenu(menu, inflater)
inflater?.inflate(R.menu.nav_overflow_menu, menu)
}
}
But it returns an error saying:
"OnBackPressed" overrides Nothing
Am I missing something? I'm already searching for the solutions but still confused over this.
Who knew... onSupportNavigateUp() works only on 4.0 and above. For below onNavigateUp() is called.
so
override fun onNavigateUp(): Boolean {
val navController = this.findNavController(R.id.myNavHostFragment)
return navController.navigateUp()
}
What you could do is set your nonbackbutton fragments to backstack when inserting them, which is done by
val transaction = supportFragmentManager.beginTransaction()
transaction.addToBackStack(null)
transaction.replace(R.id.frame, fragment) //or add, whatever you use
transaction.commit()
(if you want back button functionality, just skip the addtoBackStack line)
Then, also in your activity, you override the onBackPressed() and check whether the backstack is empty or full. If it is empty, which is checked by
if(supportFragmentManager.backStackEntryCount() == 0)
then you are, for example, on a fragment that supports back button, and just do super.onBackPressed().
On the other hand, if it has something, you can do the navController.navigateUp() part, and when done, pop it using supportFragmentManager.popBackStackImmediate().
I think you could make something like this work, try it, and let us know :)
So, I use the latest version of androidstudio and kotlin.
I created a bottom navigation activity project, and I use the activity with the drefault generated code.
I would like to open/replace a fragment from another fragment by button.
But the previous fragment doesn't disappear, when the new fragment is appear, so both are visible.
I read a lot, but I don't know the solution, please help me with some advice.
This is my MainActivity
override fun onCreate(savedInstanceState: Bundle ? ) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
val navView: BottomNavigationView = findViewById(R.id.nav_view)
val navController = findNavController(R.id.nav_host_fragment)
// Passing each menu ID as a set of Ids because each
// menu should be considered as top level destinations.
val appBarConfiguration = AppBarConfiguration(setOf(
R.id.navigation_advertisements, R.id.navigation_own_advertisements, R.id.navigation_chat, R.id.navigation_party, R.id.navigation_settings))
setupActionBarWithNavController(navController, appBarConfiguration)
navView.setupWithNavController(navController)
}
And this is my fragment
override fun onViewCreated(view: View, savedInstanceState: Bundle ? ) {
super.onViewCreated(view, savedInstanceState)
button.setOnClickListener {
activity!!.supportFragmentManager
.beginTransaction()
.replace(R.id.nav_host_fragment, ChatFragment())
.commit()
}
}
I am trying to implement Nagivation from Android Architecture Components. I am able to navigate successfully across my fragments. I am trying to attach it to my bottom navigation but I am unable to use it properly. I can navigate between fragments successfully with Navigation.findNavController(View).navigate(R.id.Fragment) but when I do that by using any UI component or back button, a highlight from my bottom navigation is not changing as shown in the following gif
My code is as follows for MainActivity.kt,
class MainActivity : AppCompatActivity() {
private lateinit var navController: NavController
private val mOnNavigationItemSelectedListener = BottomNavigationView.OnNavigationItemSelectedListener { item ->
when (item.itemId) {
R.id.navigation_home -> {
navController.navigate(R.id.homeFragment)
return#OnNavigationItemSelectedListener true
}
R.id.navigation_dashboard -> {
navController.navigate(R.id.addEmotionFragment)
return#OnNavigationItemSelectedListener true
}
R.id.navigation_notifications -> {
return#OnNavigationItemSelectedListener true
}
}
false
}
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
navController = Navigation.findNavController(this, R.id.nav_host)
navigation.setOnNavigationItemSelectedListener(mOnNavigationItemSelectedListener)
}
}
For HomeFragment.kt
class HomeFragment : Fragment() {
override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?,
savedInstanceState: Bundle?): View? {
// Inflate the layout for this fragment
return inflater.inflate(R.layout.fragment_home, container, false)
}
override fun onActivityCreated(savedInstanceState: Bundle?) {
super.onActivityCreated(savedInstanceState)
button.setOnClickListener {
Navigation.findNavController(it).navigate(R.id.addEmotionFragment)
}
}
}
Try to use navigation-ui.
implementation 'androidx.navigation:navigation-ui:' + navigationVersion //currently 1.0.0-alpha05
in activity
navController = Navigation.findNavController(this, R.id.nav_host)
NavigationUI.setupWithNavController(bottomNavigation, navController)
And make sure your fragment id match menu id.
<item
android:id="#+id/homeFragment"
android:title="Home"/>
You need to manually set a checked property inside your button click like:
button.setOnClickListener {
Navigation.findNavController(it).navigate(R.id.addEmotionFragment)
.... (Over Here)
}
The Java Code would be:
MenuItem menuItem = YourBottomViewObject.getMenu().getItem(1);
menuItemsetChecked(true);
MenuItem menuItem = YourBottomViewObject.getMenu().getItem(0);
menuItemsetChecked(false);